/*
 * Copyright � 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace Spring.Objects.Factory.Config;

/// <summary>
/// Specifies how instances of the
/// <see cref="Spring.Objects.Factory.Config.PropertyPlaceholderConfigurer"/>
/// class must apply environment variables when replacing values.
/// </summary>
/// <author>Mark Pollack</author>
[Serializable]
public enum EnvironmentVariableMode
{
    /// <summary>
    /// Never replace environment variables.
    /// </summary>
    Never = 1,

    /// <summary>
    /// If properties are not specified via a resource,
    /// then resolve using environment variables.
    /// </summary>
    Fallback = 2,

    /// <summary>
    /// Apply environment variables first before applying properties from a
    /// resource.
    /// </summary>
    Override = 3
}
